See comments below [DA:]
Denis Anson, MS, OTR/L
Assistant Professor
College Misericordia
301 Lake St.
Dallas, PA 18612
-----Original Message-----
From: w3c-wai-ua-request@w3.org [mailto:w3c-wai-ua-request@w3.org] On
Behalf Of Hansen, Eric
Sent: Wednesday, May 23, 2001 8:43 AM
To: 'Ian Jacobs '; 'w3c-wai-ua@w3.org '
Subject: RE: Checkpoint 4.6: Proposed clarifications
Sound reasonable. See note "EH:" below.
-----Original Message-----
From: Ian Jacobs
To: w3c-wai-ua@w3.org
Sent: 5/22/01 1:11 PM
Subject: Checkpoint 4.6: Proposed clarifications
Hello,
In the 11 April 2001 draft [1] of UAAG 1.0, checkpoint 4.6 reads:
4.6 For graphical viewports, allow the user to position text
transcripts, collated text transcripts, and captions in
the viewport. Allow the user to choose from among at least
the range of positions available to the author (e.g.,
the range of positions allowed by the markup or style
language).
Based on discussion and resolutions at the 19 April
2001 teleconference [2], I am trying to clarify the checkpoint.
The fully revised checkpoint is at the end of this email.
Things to take into account:
0) This checkpoint is about control of captions position with
respect to one or more synchronized visual tracks (and not
just any other piece of content). This checkpoint is
for graphical viewports only.
1) This checkpoint should only be about synchronized text tracks,
not [collated] text transcripts. I think the whole point of this
checkpoint is to ensure that synchronized information is both
legible and nearby. I think that in general, authors will specify
captions to accompany a visual track (in the same viewport), but
not transcripts.
Proposed: Drop text transcripts and collated text transcripts
from this checkpoint. Note that checkpoint 2.5 also refers to
[collated] text transcripts and should continue to do so: this
ensures that they are available at the same time as a visual
track.
2) Respect the author's positions and styles (e.g.,
colors, etc.) as expressed in the content. However, allow
the user to override the author's specified position.
[DA: If we allow override of the author's position, we also need to
allow override of style. You can make text just as impossible to read by
choosing a style that is not perceptible to an individual as by choosing
a position that makes life difficult.]
4) The user agent is not required to lay out other content
(i.e., reflow) after the user has changed the position of
captions.
5) If the user agent satisfies this checkpoint by using a markup
language or style sheet language for control, then the user agent
must allow the user to choose from among at least the range of
positions enabled by the format.
6) If the user agent satisfies this checkpoint otherwise (e.g.,
by making available captions in a separate viewport), then
the user agent must:
a) Allow the user to position the captions to
overlap the visual track. The captions background
should be transparent to allow the visual track
to show through.
[This capability might bite a user. If the captions have a transparent
background, there will be times where the captions and the background
form a color combination that cannot be seen. As an option, this might
be OK, but you would also want the option of having a fixed background
color for the captions, so that they are always readable, regardless of
the visual track changes.]
b) Allow the user to position the captions to
not overlap the visual track.
7) The checkpoint should allow for configuration or control.
Given all of this:
<NEW 4.6>
For graphical viewports, allow the user to position captions
with respect to synchronized visual tracks as follows: If the
user agent satisfies this checkpoint by using a markup
language or style sheet language to provide configuration or
control, then the user agent must allow the user to choose
from among at least the range of positions enabled by the
format. Otherwise, the user agent must allow both
non-overlapping and overlapping positions (e.g., by rendering
captions in a separate viewport that may be positioned on top
of the visual track). The user agent must allow the user to
override the author's specified position. The user agent is
not required to change the layout of other content (i.e.,
reflow) after the user has changed the position of captions.
Note: When captions overlap the synchronized visual track,
the user should be able to view the visual track behind
the captions. Refer to checkpoint 4.3 for requirements
related to the control of background colors.
</NEW 4.6>
EH: May need to clarify that the Note does not mean that the lettering
needs to be translucent or transparent.
- Ian
[1] http://www.w3.org/WAI/UA/WD-UAAG10-20010411/
[2] http://lists.w3.org/Archives/Public/w3c-wai-ua/2001AprJun/0046
--
Ian Jacobs (ij@w3.org) http://www.w3.org/People/Jacobs
Tel: +1 831 457-2842
Cell: +1 917 450-8783